Stereoregular polyolefin compositions



United States Patent Office 3,316,328

Patented Apr. 25, 1967 3,316,328 STEREOREGULAR POLYOLEFIN COMPOSITIONSJack J. Press, Teaneck, N.J., assignor to Iowa Manufacturing Company,Cedar Rapids, Iowa No Drawing. Filed Nov. 30, 1964, Ser. No. 414,919 6Claims. (Cl. 260-895) This application is a continuation-in-part of mycopending application Ser. No. 113,972, filed Apr. 4, 1961, nowabandoned.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

This invention relates to stereoregular polyolefins. More particularly,this invention relates to polymeric compositions having improvedafiinity for dyes, said compositions containing a major amount ofstereoregular polyolefins.

It is known that polyethylene is unsuitable for the production oftextile fibers due to the relatively poor properties imparted to theproduct. For one thing, staple po yethylene fiber will not hold a crimpand this is necessary for textile processing. For another, it is uselessto make a textured or stretch yarn from a continuous filamentpolyethylene yarn because the characteristics imparted to the yarn arenot maintained during weaving, dyeing, or ordinary use. Further, thematerial from which a fabric is made must be thermally stable before itmay be subjected to ordinary use. It must not have a relatively lowmelting point, and the final fabric must not have a high degree of heatsensitivity, nor relatively soft mechanical properties at elevatedtemperatures. However, the thermal properties of a polyethylene fabricare such that it is impossible to subject it to ordinary ironing withoutphysically damaging the fabric and it has been found to shrink in theconventional dryer. As is apparent from the foregoing, polyethylenecannot be utilized in the manufacture of everyday fabrics for ordinaryuse.

In recent times, it has been found that certain linear crystallinehydrocarbon polymers containing stereoregular macromolecules and havingmelting points between 150 and 300 C. can be used for the production oftextile fibers without the inherent difficulties encountered with theuse of polyethylene polymers for this purpose. Aside from melting pointdifferences, polypropylene with a tertiary carbon and a methyl sidechain, crystallizes differently and has a much higher resilience andelasticity. These properties are essential in generally useful textilefiber. Further, polymers of olefinic hydrocarbons containingstereoregular macromolecules, such as polypropylene, polymethylpentene,and polymethylbutene otter considerable advantages in the production offibers, particularly because of their good mechanical properties andlightweight. However, such polymers have not been satisfactory becauseof their poor afiinity for dyes, this poor atfinity being due to theparticular chemical nature of such polyolefinic hydrocarbons.

Many processes have been proposed in order to improve the afiinity ofsuch polyolefinic hydrocarbons for dyes, such as the addition of solublesolid substances to the molten polyolefin before spinning. The additionof basic substances facilitates dyeing with acid dyes, whereas theaddition of acid substances favors dyeing with basic dyes. However, suchprocesses have not been completely satisfactory because solublemodifiers interfere with crystallization, impair strength and are notsutficiently available in the amorphous regions where dyeing takes lace.

p It has also been proposed to increase the afiinity for dyes ofpolyolefin fibers by grafting monomers onto the fiers having fibersafter subjecting the fibers to a preliminary peroxidation or to highenergy radiation. When such processes are applied to the polyolefin,after it is in filamentary orm, the surface properties of the graftedfibers are considerably modified and the dye receptivity is improved.However, when such processes are applied to highly crystallinefilaments, any grafting onto the preformed fibers takes place only atthe surface. Therefore, subsequent dyeing is limited to the surfaceportion of the fiber and the dye does not penetrate inside the fiber.

In my copending application titled Modification of StereoregularPolyolefins, Ser. No. 400,611, filed Sept. 30, 1964, I show the use ofselected hydrophilic polymers to improve the dyeability ofstereoregular, high melting, polyolefins. The level of addition rangesfrom 2 to 20% by weight based on the polyolefin. However, myhydrophilic, polymeric, modifiers show only limited dyeability withselected small disperse dyes, and only negligible dyeability with largerionic dyes such as acid, basic, premetallized and direct dyes. Thelatter dyes are particularly desirable because of their generally betterwash, dry clean, and light fastness properties. The depth and range ofdyeability can be increased somewhat by increasing either the molecularweight or the level of addition of the primary modifier. However,increasing the molecular weight makes melt dispersion more diificult andincreased levels of addition are not economically feasible and adverselyaffect physical properties, particularly fibrillation.

In another of my copending applications titled Modification ofStereoregular Polyolefins With Synergistic Combinations, Ser. No.406,631, filed Oct. 26, 1964, I teach that, even at low levels ofaddition, I obtain synergistic improvements in dyeability by replacingbetween 5% and 50% 0f the above primary hydrophilic modifiers withselected liquid, wax, or polymeric secondary modinegligible dyeabilityby themselves. These secondary modifiers are generally low molecularweight additives or possess melting points somewhat lower than thepolyolefin itself. These secondary additives associate themselves withthe primary hydrophilic polymeric modifier in such a way as to givesynergistic combinations that are fusible at temperatures not exceedingthe temperature of processing of the polyolefin and have improvedprocessability and dyeability.

However, for optimum efiiciency, the primary hydrophilic polymer and thesecondary additives must be chosen and processed so that, when dispersedin the polyolefin, the primary and secondary additive will interactuniformly and efficiently to give a complex with improved synergisticutility. In actual practice, it is somewhat difficult to achieve andmaintain optimum complex formation before and during melt mixing withthe polyolefin. In addition, secondary additives which have notcomplexed with the hydrophilic polymer may sweat out of the polyolefinand interfere with processing.

Now, I have discovered that the afiinity of the polyolefins for dyes maybe further improved, over and above the improvement achieved with theabove polymeric materials, and comparable with the improvement achievedwith the above secondary polar additives, if the modifier incorporatedin thepolyolefin is one of a specified class of copolymers. Thus, thedifiiculties encountered with the use of secondary additives areeliminated while the improvement achieved is maintained. As an addedadvantage, the amount of modifier necessary to achieve a given level ofdyeability is reduced. Also, the elimination of secondary additivestends towards greater uniformity in dyeing when the polyolefiniccombination is processed under high speed commercial operations.

It is therefore an object of this invention to provide a polymericcomposition having improved affinity for dyes evoid of the diflicultiesof the prior art heretofore escribed.

This invention relates to stereoregular polyolefins hav- 1g increasedaffinity for dyes and other polar substances omprising:

A matrix of a stereoregular polyolefin taken from the ;roup consistingof polypropylene, polymethylpentene, tl'ld polymethylbutene, said matrixof polyolefin having lispersed therein between about 2% and 20% of amodi- Tying copolyrner derived from the combination of an )xygencontaining N-alkenyl heterocyclic monomeric unit with a monomeric unitcontaining an amino nitrogen, said :opolymer selected from the groupconsisting of:

[1) 80% N-vinyl pyrrolidone/20% dimethylaminoethyl methacrylate,

(2) 95 N-vinyl pyrrolidone/ trimethylaminoethyl methacrylate,

(3) 85% N-vinyl pyrrolidone/ trimethylaminomethyl styrene,

(4) 80% N-vinyl pyrrolidone/ methyl ethyleneimine,

(5) 80% N-isoprenyl pyrrolidone/ 20% diethylaminoethyl acrylate,

(6) 70% N-isoprenyl pyrrolidone/% dimethylaminoethyl acrylamide,

(7) 90% N-acrylyl pyrrolidone/l0% N-vinyl pyrrole,

(8) 90% N-vinyl methylpyrrolidone/10% lauryldimethylarninoethylmethacrylate,

(9) 70% N-vinyl morpholine/30% N-vinyl ca-rbazole,

(10) 70% N-vinyl morpholinone/ 30% N-vinyl indole,

(11) 70% N-vinyl morpholinone/ 30% N-butyl vinyl quinoline,

(12) 80% N-vinyl caprolactam/ 20% N-methyl vinyl imidazole,

(13) 80% N-vinyl caprolactam/20% N-vinyl succinimide,

(14) 95% N-vinyl oxazolidinone/5% laurylaminoethyl methacrylate,

(15) 90% N-vinyl morpholinone/ 10% aminoethyl methacrylate,

(16) 70% N-vinyl benzamidazole/ 30% N-vinyl diphenylamine,

(17) 70% N-vinyl phthalamide/ 30% piperidine,

(18) 90% N-vinyl diglycolimide/10% dimethyl 2-vinyl pyridine,

(19) 70% N-vinyl methylpyrrolidone/ 30% butylaminoethyl methacrylate,

(20) 90% N-vinyl pyrrolidone/10% 2-vinyl pyridine,

all said percentages being percent by weight.

My selected copolyrner modifiers contain at least 70% of an oxygencontaining N-alkenyl heterocyclic monomeric unit in order to obtain gooddye penetration without surface blocking, strong dye afiinity and goodwash, dry clean, and light fastness. Also, my selected copolymericmodifiers, which should have a molecular weight of at least 10,000, andpreferably over 20,000, are strongly hydrophilic, generally soluble inwater or an oxygenated solvent, fusible, insoluble but dispersible inpolyolefin, and possess melting points of at least 50 C. but preferablyover 100 C.

The stereoregular polyolefins which may be used within the concept ofthis invention include isotactic and syndiotactic polyolefins. Thesematerials are usually made by utilizing stereo-specific catalysts whichgive polymers which are substantially linear and which develop a highdegree of crystallinity.

The following examples will illustrate the utility of the presentcomposition.

butyldimethyl- N-methyl vinyl Example 1 Using conventional solutionpolymerization procedures, a 50% by weight solution in ethyl alcohol ofa 80/20 weight ratio of N-vinyl pyrrolidone/dimethylaminoethylmethacrylate copolyrner was prepared. The copolyrner had a molecularweight of 40,000.

An aliquot of the above solution was poured into a shallow pan and driedin a forced air circulation oven at a temperature of 50 C. The solidpolymer sheet was broken up and then ground in a centrifugal grinder togive a powder passing through a 50 mesh screen.

Portions of the copolymers, in solution and ground forms, were combinedin several variations with a representative stereoregular polyolefin,processed into fiber and evaluated using the following procedure:

(a) Fourteen parts of the 50% ethyl alcohol copolyrner solution wasuniformly mixed in a laboratory mortar with 93 parts of a powdered (50to 200 mesh) commercial isotactic polypropylene (molecular weight ofabout 350,000; melting point of about 170 C.; melt flow index of 3.3;and isotacticity of 95%).

(b) The polypropylene-modifier mixture was overnight and then dried inan oven at all of the solvent had been removed.

(c) The coated dry powder was then melt mixed in a screw extruder,forced through a die at 260 C., and collected at ambient temperature ona reel as a 30 denier filament. The filament was heat stretched 300% togive a strong, oriented 10 denier fiber and was then wound into skeinsfor use in evaluating uniformity of dispersion and dyeability.

(d) The fiber skeins were scoured with detergent at 80 C., dyed at theboil for one hour at a 20 to 1 bath to fiber ratio with representativedye solutions, and then well scoured to remove any surface dye. The dyedfiber was then evaluated for laundering (74 C.), dry cleaning (Stoddardand perchlorethylene solvents), and light fastness using standardprocedures.

One to eight percent dyeings, on weight of fiber (o.w.f.) were carriedout with the following dyes:

air dried C. until excellent=xxx) was assigned for each dyestuff classbased on dyestufi exhaustion and build-up, as well as, wash, dry cleanand light fastness as follows:

Dyestufi Class Premet- Disporse Acid allized Mordant Direct Acid Ratingxxx xx xxx xx xx As indicated, the polymeric modifier increased theaffinity of the polyolefinic composition for dyes in general.

Example 2 In accordance with Example 1, the predried and groundcopolymeric modifier was mixed with the polyolefin, processed andevaluated. For comparison purposes, a similarly prepared polyvinylpyrrolidone homopolymer (2d) Was also evaluated after similarprocessing. The results of the evaluation are tabulated below:

TABLE Dyestnff Class Percent Dispersibility Percent Sample Add inPolyolefin of A Disperse Acid Prcrnetal- Mordant Direct lized Acid 2Excellent 1.6 5 4 l 8 5 1 N vinyl pyrrolidone.

As is apparent from the table above, the homopolymer (polyvinylpyrrolidone) was not uniformly dispersed and did not dye as well as thecopolymer (80% N-vinyl pyrrolidone/% dimethylaminoethyl methacrylate).

Example 3 In accordance with the procedure of Example 1, similar testswere made and the results were set forth in the table which follows: Inthis case, the modifiers utilized were the copolymers heretofore listedin Markush I 14Apolyvinyl oxazolidinone l5A-polyvinyl morpholinone16A--polyvinyl benzamidozole 17A-polyvinyl phthalamide ISA-polyvinyldiglycolimide 19A-p0lyviny1 oxazolidone As is apparent from the tablebelow, the copolymeric modifier in all cases increased the afiinity ofthe composition for dyes over and above the level achieved when themodifier utilized represented a corresponding homopolymer.

Example 4 In accordance With the procedure of Example 1, fiber sampleswere prepared and tested at the 5% level with the following modifiers,viz. (4a) a copolymer of N-vinyl pyrrolidone with 10% Z-Vinylpyridine,(4b) a 2-vinylpyridine homopolymer, (4c) a polyethylene imine and (4d) apolydimethylaminoethyl methacrylate. The

TABLE Dyeability with- Percent Modifier ratio Percent PercentDispersibility in Pre (if any) add A 1 Polyolefin Acid metaldyes lizedacid dyes 7 6. 7 Fair xxx xxx 7 7 Poor. x x 3 2.6 Cut/ex. xx xx 3 3Poor/fair. O 5 4 00d i xx xx 4 4 P0or/fair 0 5 4 00d. xx 4 4 Poor/fair.0 3 2. 1 Excellent xx 2 2 Poor/fair 0 l0 9 Fair/good xxx 9 9 ery poor x10 9 00d xxx 9 9 Very poor x 5 3. 5 Good/excel xxx 3. 5 3. 5 oer/fair 07 4. 9 Good xxx 5 5 Poor. 0 5 3. 5 Good/excel xx 3. 5 3. 5 Poor/fair 0 75. 6 Goodxx 6 6 Poor x 10 8 Good xxx 8 8 Very poorx 15 14 Fair/good. xxx15 15 Very poorx 10 9 Good.. xxx

9 9 Very poor x 5 3. 5 Good/excel xx 3. 5 3. 5 Poor/faiL 0 5 3. 5Good/excel xxx 3. 5 3. 5 Poor/fair. x 10 9 Fair/good xxx 9 9 ery p0or x7 4.9 Good xxx 5 5 Poor x 1 Oxygen containing N- heterocyclic monomericunits vmples were dyed accordingly and the ratings are listed the tablewhich follows:

Dyestufi Class Modifier Premetal- Direct lized Acid Disperse AcidMordant NOTE: The more basic polyvinylpyrridine, polyethylene imine, andolydimethylaminoethyl methacrylate, gave poor to fair dyeability ecauseof greater solubility in the polyolefin and a tendency to surface yeblockage. My more hydrophilic, less basic modifiers are less soluble 1the polyolefin, and concentrate in the amorphous regions where they Manyalternate methods of combining my modifiers Nith polyolefins are readilyavailable. They may be comained during formation of the polymericmodifier or during actual polymerization of the polyolefin, with orwithout melting. They may be added to freshly polymerized polyolefin,which is still in solution in a suitable solvent, in the powdered form,or as a solution in a compatible solvent, or merely as a dispersion.They may be added to the polyolefin during precipitation, washing,neutralizing or compounding of the freshly prepared polyolefin prior todrying. This may be accomplished by adding the modifier as a powder oras a solution which is a non-solvent for the polyolefin.

The modifiers may also be melt mixed during processing or blending ofthe polymer prior to use in extrusion of fiber, film, coating orplastic. It may also be added as a liquid or powder to finely ground ormicronized polyolefin polymers and then melt dispersed in situ duringhot dip or spray coating or during spreading and heat coating operation.They may be incorporated in polyolefin solutions or emulsion and thenapplied to surfaces with or without heating.

The level of addition of the modifiers heretofore listed should bebetween 2 and 20% of the weight of the overall composition. If less than2% is utilized, significant improvement will not be achieved indyeability. If an amount greater than 20% is added to the polyolefin,many of the physical properties of the final product, such as fiber orfilm, are adversely affected. These include loss of strength and a lowerresistance to repeated flexing.

The copolymer should contain between 70% and 99% by weight of an oxygencontaining N-heterocyclic monomeric unit at which level improveddyeability may be achieved without post treatments and surface blockage.If the copolymer contains between 1% to 30/ of a basic monomeric unit,this will contribute towards improved afiinity for acid dyes.

However, if the basic monomeric unit is present in an amount greaterthan 30% by weight, there will be excessive problems in processing. Forinstance, the modifier will be highly soluble in the polyolefin and lesseffective in concentration in the amorphous region where needed forimproved dyeability. This will be accompanied by excessive surfaceblockage. Also, if the monomeric unit of a basic nature is present inless than 1% by weight of the copolymer, there will be no appreciablebenefit achieved in dyeability.

Prior efforts to develop polymeric modifiers for high meltingpolyolefins have stressed development and use of specific polymers withrelatively high solubility in the polyolefin. These modifiers includedpolyimines and polyvinylpyridines.

Polyimines have high molecular mobility which appatently gives them somecase of solution in polyolefins. However, this is also a high tendencyto sweat out and separate when the combination is made into fiber orfilm. This material also gives high surface blockage and excessivecracking. On the other hand, soluble polyvinylpyridines confer little orno dyeability on the polyolefin when dissolved therein. This appears tobe the case until the preformed modified polyolefin is post treated withepoxy compounds, concentrated acids, .alkylating agents, nitrous oxidegas, and alkylene oxides. However, such post treatments are difficult,costly and generally impractical.

Under present concept, I prefer hydrophilic polymeric modifiers whichmay be soluble in either water or an oxygenated solvent but which arenot soluble in the polyolefin. I do prefer modifiers which are fusibleand can be dispersed in the polyolefin.

Prior experience with comparatively less hydrophobic fiber formingpolymers, such as polyacrylonitrile polymers and polyamides, have shownthat the use of hydrophilic, water soluble or dispersible modifiers isimpractical, mainly, because excessive amount of the modifier areleached out in scouring and dyeing processes. Surprisingly, I have foundthat my hydrophilic polymeric modifiers, when melt dispersed in the morehydrophobic polyolefin, have good dispersion stability and are notsusceptible to leachage.

I have found that at comparatively low levels of addition, my modifiersconfer good dyeability on the polyolefin without the necessity forcostly and sometimes impractical post treatments.

My hydrophilic modifiers must be fusible with the polyolefin. This isnecessary for the formation of a continuous network of modifiersthroughout the poloyolefin in order to permit dye penetration andefficient coordination of the dye and modifier throughout the film orfiber.

The use of a non-fusible cross-linked modifier, which results in poordispersion, is ineffectual. The required modifier network in such a casecannot be formed and the discrete separate particles are surrounded byunmodified areas within the polyolefin matrix. As a result, dyeing islimited to the fiber surface and the dye cannot penetrate into theinterior of the fiber where it is most desired.

It is generally recognized that dyeing takes place almost entirely inthe more open and readily accessible amorphous areas. When a solublemodifier is utilized, it is usually spread throughout the amorphous andcrystalline areas of the polyolefin. As a result, the modifier in thecrystalline areas is not available for improvement in dyeability. Italso interferes with crystallization and adversely affects strength andthermal stability. However, my non-soluble, hydrophilic, polymericmodifiers are not sufficiently compatible to be a part of the moreuniform and denser crystalline areas. It appears to concentrate in themore amorphous areas where it is necessary for dyeability. It has alsobeen found that an increase in molecular weight of my modifiers, furtherreduces compatibility with stereoregular polyolefins and promotesconcentration of the modifier in the more amorphous regions where it mayimprove the dyeability of the polyolefinic matrix.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teaching. For instance, themodifiers of this invention may be used to increase opacity and theaffinity of the polyolefin for finishes. They may also be used toimprove the printable of the polyolefin, increase the adhesion of thepolyolefin to other materials, or to reduce the overall staticpropensity of the final product. It is therefore to be understood thatwithin the scope of the appended claims, the invention may be practicedotherwise than as specifically described.

I claim:

1. A polymeric composition having improved affinity for dyes comprisinga matrix of stereoregular polyolefin taken from the group consisting ofpolypropylene,

polymethylpentene, and polyrnethylbutene;

said matrix having dispersed therein between 2% and 20% of a copolymerselected from the group consisting of: (a) 80% N-vinyl pyrrolidone/20%yl methacrylate, (b) 80% N-vinyl pyrro1id0ne/20% methyl ethyleneimme,(c) 70% N-isoprenyl pyrrolidone/30% noethyl acrylamide, (d) 90% N-acrylyl pyrrolidone/ 10% (e) 70% N-viny1 morpholine/30% N-vinylcarbazole, (f) 70% N-vinyl morpholinone/30% N-butyl vinyl quinoline, (g)80% N-vinyl caprolactam/20% N-vinyl succinimide, (h) 95% N-vinylXazolidinone/5% methacrylate, (i) 70% N-vinyl methylpyrrolidone/30%ethyl methacrylate, and (j) 90% N-vinyl pyrrolidone/ 2-vinyl pyridine,all said percentages being by weight. 2. The combination of claim 1wherein said copolymer is 80% by weight N-vinyl pyrrolidone incombination with dimcthylaminoethyl methacrylate.

dimethylaminoethdimethylami- N-vinyl pyrrole,

laurylaminoethyl butylamino- 3. The combination of claim 1 wherein saidcopolymer IS 95% by weight N-vinyl oxazolidinone in combination with 5%by weight lauryla minoethyl methacrylate.

4. The combination of claim 1 wherein said copolymer is 70% by weightN-vinyl morpholine in combination with by weight N-vinyl carbazole.

5. The combination of claim 1 wherein said copolymer is by weightN-vinyl morpholinone in combination with 30% by weight N-butyl vinylquinoline.

6. The combination of claim 1 wherein said copolymer is by weightN-vinyl caprolactam in combination with 20% by weight N-viny1succinimide.

References Cited by the Examiner UNITED STATES PATENTS 2,527,863 10/1950Webb 260-895 2,628,214 2/1953 Pinkney et a] 260-897 2,927,904 3/ 1960Cooper 260889 3,003,845 10/1961 Ehlers 260-895 3,022,267 2/1962 Young260895 3,115,478 12/1963 Ginstiniani 260-895 FOREIGN PATENTS 1,228,5393/1960 France.

834,160 5/1960 Great Britain.

850,435 5/1960 Great Britain.

MURRAY TILLMAN, Primary Examiner. D. J. BREZNER, Assistant Examiner.

1. A POLYMERIC COMPOSITION HAVING IMPROVED AFINITY FOR DYES COMPRISING AMATRIX OF STEROREGULAR POLYOLEFIN TAKEN FROM THE GROUP CONSISTING OFPOLYPROPYLENE, POLYMETHYLPENTENE, AND POLYMETHYLBUTENE; SAID MATRIXHAVING DISPERSED THEREIN BETWEEN 2% AND 20% OF A COPOLYMER SELECTED FROMTHE GROUP CONSISTING OF: (A) 80% N-VINYL PYRROLIDONE/20%DIMETHYLAMINOETHYL METHACRYLATE, (B) 80% N-VINYL PYRROLIDONE/20% METHYLETHYLENEIMINE, (C) 70% N-ISOPRENYL PYRROLIDONE/30% DIMETHYLAMINOETHYLACRYLAMIDE, (D) 90% N-ACRYLYL PYRROLIDONE/10% N-VINYL PYRROLE, (E) 70%N-VINYL MORPHOLINE/30% N-VINYL CARBAZOLE, (F) 70% N-VINYLMORPHOLINONE/30% N-BUTYL VINYL QUINOLINE, (G) 80% N-VINYLCAPROLACTAM/20% N-VINYL SUCCINIMIDE, (H) 95% N-VINYL OXAZOLIDINONE/5%LAURYLAMINOETHYL METHACRYLATE, (I) 70% N-VINYL METHYLPYRROLIDONE/30*BUTYLAMINOETHYL METHACRYLATE, AND (J) 90% N-VINYL PYRROLIDONE/10%2-VINLY PYRIDINE, ALL SAID PERCENTAGES BEING BY WEIGHT.